1. Field of the Invention
The invention generally relates to a driving mechanism of an optical disc driver, and particularly relates to a mechanism for driving an optical head of an optical disc driver, such as for compact disc, DVD, CD-R/RW, DVD-RW, DVD-RAM, MO, Mini Disk or Slim-type DVD.
2. Related Art
A conventional mechanism for driving an optical pickup head or writing head of an optical disc driver, as shown in FIG. 1, generally includes a base plate 1, an optical module 2 (including a writing or pickup head 21), motor and gears 3 and a rack 4. The optical module 2 is movably mounted on a pair of guide rods 11, 11xe2x80x2. The gears 3 are pivotally mounted on the base plate 1 at one side of the optical module 2. The rack 4 is connected to the optical module 2 and resiliently engaged with a part of the gears 3 by force of a pressing spring 41. When the motor and gears 3 drive, the rack and the optical module 2 is moved along the guide rack 11, 11xe2x80x2.
However, the aforesaid conventional diving mechanism has the following disadvantages:
1) The mechanism is complicated since there are many components;
2) It is hard to be minimized in size or made thinner since the components;
3) It is hard to improve the mechanism precision since there are larger tolerance in the motor, gears and rack;
4) It is higher in cost since there are so many components to be prepared and assembled.
Therefore, we need an optical head driving mechanism for an optical disc driver that has simpler composition, smaller and thinner size, higher precision and lower cost to overcome the aforesaid drawbacks.
The major object of the invention is to provide an optical head driving mechanism for an optical disc driver that has simple composition so as to reduce its size.
An optical head driving mechanism for an optical disc driver according to the invention is applied to an optical disc driver having a base plate, a pair of guide rods mounted on the base plate, and an optical module movably mounted on the guide rods. The optical module, including an optical head, is connected and driven by a driving mechanism. The driving mechanism includes a base, a movable member, a piezo-actuator and at least a resilient member. The base is fixed to the base plate. The movable member, having a plurality of first connection portions, is movably mounted on the base. The piezo-actuator, having a plurality of second connecting portions corresponding to the first connecting portions, contacts the optical module. The first connecting portions of movable member and the second connecting portions of the piezo-actuator connect to each other and act as reflection points of wave transference so as to provide proceeding waves at the rim of the piezo-actuator and move the optical module along the guide rods when the piezo-actuator activates. The resilient member is held by the base and the movable member so as to provide pressing force as suitable friction between the piezo-actuator and the optical module for transferring the proceeding waves.